import type { WorkflowDefinitionSnapshot } from "../workflows/types.js";
/**
 * Graph layout for the terminal viewer, ported from the acpx replay viewer's
 * view-model (expand switch edges, classify back edges via shortest levels,
 * longest-path layering with terminal tail pull-down, barycenter ordering).
 * The one addition is virtual pass-through cells so every forward edge spans
 * exactly one rank, which keeps text routing local to each rank gap.
 */
export type GraphEdge = {
    edgeId: string;
    from: string;
    to: string;
    /** Switch case key for labelled branches. */
    label?: string;
    isBackEdge: boolean;
};
export type GraphCell = {
    kind: "node";
    nodeId: string;
} | {
    kind: "virtual";
    edgeId: string;
};
export type GraphSegment = {
    edgeId: string;
    /** Rank index the segment starts at; it ends at `rank + 1`. */
    rank: number;
    fromCell: number;
    toCell: number;
    /** Label to draw on this segment (only on the first segment of an edge). */
    label?: string;
};
export type GraphLayout = {
    ranks: GraphCell[][];
    edges: GraphEdge[];
    /** Forward-edge segments between adjacent ranks. */
    segments: GraphSegment[];
    /** Rank index of every real node. */
    rankOfNode: Map<string, number>;
};
export declare function expandEdges(snapshot: WorkflowDefinitionSnapshot): GraphEdge[];
/**
 * Build ranks with virtual pass-through cells so every forward edge connects
 * adjacent ranks, then order cells within ranks by neighbor barycenter.
 */
export declare function layoutGraph(snapshot: WorkflowDefinitionSnapshot): GraphLayout;